1. Field of the Invention
This disclosure relates to a semiconductor package and, more particularly, to a tape package used in a liquid crystal display (LCD) and a method for testing the same.
2. Description of the Related Art
Recently, rapid development of LCD technology has brought about an advancement in information society. Generally, electrical devices in which an LCD is mounted for information transmission, are required to be thin, light-weight, and small. Thus, semiconductor packages using a new mounting method have been developed in the semiconductor packaging field.
Conventionally, micro ball grid array (m-BGA) packages were mainly used in electrical devices in which an LCD was mounted for information transmission. However, lately, tape packages using a new mounting method are mainly being used. With tape packages, a semiconductor chip is directly attached to a film with a thin tape-like shape. Such tape packages do not use solder balls as an external connection terminal. Instead, a copper interconnection pattern formed on the film is directly attached to a printed circuit board (PCB) or an LCD panel. Generally, examples of the tape packages include a tape carrier package (TCP) or a chip on film (COF) package.
FIG. 1 is a plan view illustration of a film tape package according to the prior art.
Referring to FIG. 1, a copper interconnection pattern 16 is formed on a film 10 of a conventional tape package made of a bendable material, for example polyimide, and a chip paddle 18, to which a semiconductor chip is attached, is formed in the middle of the film 10. The copper interconnection pattern 16 extends a function of the semiconductor chip to the outside and is used as a contact terminal during an electric testing process. Further, the semiconductor chip is attached to the chip paddle 18 of the film 10 through a bump formed on a pad of an active area.
Gear shape holes 12 are formed on the right and left sides of the film 10. The gear shape holes 12 are used to wind a tape package, to which the semiconductor chip is attached, with a winding reel. Further, a cutting slit 14 formed inside the gear shape holes 12 is used to separate the tape package from the film 10.
In FIG. 1, reference character A1 indicates an area where a solder resist is coated. The area A1 prevents the copper interconnection pattern 16 from being oxidized when the copper interconnection pattern 16 is exposed to the outside and prevents a short-circuit of the copper interconnection pattern 16 which can be caused by foreign material. Further, reference character A2 indicates a user area which is cut from the film 10 and then used. Thus, in the tape package, which is transferred to a user in a state where the tape package is wound on a winding reel, the user cuts only the user area A2 so that the tape package is used as an LCD driving semiconductor package.
In FIG. 1, reference characters B1 and B2 indicate an external connection terminal. The external connection terminals B1 and B2 are used as adhesives, which are anisotropic and have conductivity, and are directly attached to a PCB or an LCD panel. Different from other kinds of semiconductor packages, the tape package can be mounted in a PCB or an LCD panel in a bent state, since the film 10 is made of a material which is bent easily.
Further, reference characters TP1 and TP2 indicate test pads. The test pads TP1 and TP2 are positioned outside the user area A2 and contact a needle of a probe card to test electric functionality of the tape package. Thus, a total length where one tape package occupies the film 10 is a length L1 including the length of the user area A2 and the lengths of the test pads TP1 and TP2.
The tape package according to prior art has the following problems, which are described with reference to FIGS. 1 and 2. FIG. 2 is a cross-sectional illustration of the tape package of FIG. 1 mounted to a chip.
Referring to FIG. 2, in a tape package 20 according to the prior art, a semiconductor chip 30 is attached to a copper interconnection pattern 26 of a film 10 at a bump 34, and an active area of the semiconductor chip 30 is encapsulated by an encapsulant 32. The film 10 has a cross-sectional structure that includes a base substrate 22 made of a bendable material, for example polyimide, and the copper interconnection pattern 26 laminated on a base substrate 22 using an adhesive 24.
Test pads TP1 and TP2 are cut to be separated from the tape package 20. The copper interconnection pattern 26 formed on an upper surface of the film 10 is coated with a solder resist 28 except in an area where external connection terminals B1 and B2 are formed.
Since the copper interconnection pattern 16 is formed only on one surface of the film 10, that is, the test pads TP1 and TP2 are positioned outside the user area A2, the total length L1 of the tape package becomes longer. Thus, an amount of film 10 used for manufacturing one tape package increases. In addition, since the copper interconnection pattern 16 is formed, manufacturing costs of the tape package increases.
Also, when the copper interconnection pattern 16 is cut in a process for separating the user area A2, a defect such as a burr occurs in the copper interconnection pattern 16, resulting in a short-circuit of the copper interconnection pattern 16 adjacent to the burr.
Further, different sized probe cards must be used according to a pitch between the test pads and the size of the user area in a process for testing an electric functionality of the tape package. Since in the conventional tape package, the copper interconnection pattern 16 is formed on only one surface of the film, a universal probe card cannot be used. Thus, a large number of different sized probe cards are required.
Embodiments of the invention address these and other problems in the prior art.